Blender 2.83 Displacement - Cycles and Eevee
The reason there's no error in the displacement in EEVEE is that there is no displacement in EEVEE.

So, if you like what you see there, the simplest solution is to unplug the displacement. But that's not an explanation of what's happening.

If a vector is plugged straight into the Displacement input of a Material Output node without going through a Displacement node first, what you get is a displacement of the shading-points by that vector, in Blender Units, in Object Space. (That is, along the object's local axes, and taking the object's scale transform into account). 

You can get the feel of that by plugging a Combine XYZ node into the Displacement input, and playing with the numbers.

It looks as if you would probably want simple displacement along the normals of your surface here -  there are no undercuts. So, if you did want to displace the inside surface of the glass, you would have a UV map of the lens which separated the inside and outside surfaces, and, covering the region of the map representing the inside surface, have an image which would serve as a height map, with 0 values interpreted as no displacement, and 1 values as full displacement. 

You would then plug that map into the Height input of a Displacement node, and in turn, plug the Displacement node onto the Material Output.